For background on AOS systems see Corrado et al., U.S. Pat. No. 5,482,314. Such systems produce a signal for input to the airbag deployment system (ADS), which if the occupant is out of position (OOP) or in a rear facing infant seat (RFIS) (in the front seat of a vehicle), the deployment of the airbag is aborted, deferred or otherwise controlled. Such deployment systems are known as Smart Airbag Systems (SAS), and may respond to AOS signals by a decision process to: deploy or not (abort deployment), or modify deployment for dual phase airbags, multiphase, or for partial or controlled rate inflation airbags.
Recent studies have revealed that there is a class of slow speed automotive accidents causing injury to children, youngsters and frail adults. This usually occurs when the .DELTA.V of the "crash" is 18 miles per hour or less, where the occupant is unbelted or in an RFIS and the driver jams on the brake. The airbag deployment sensor experiences a G-force great enough to signal deployment. Typically, in the low speed accident, the child has slid, or is sliding forward into the Instrument Panel (IP) when the airbag deploys. The airbag deployment injures the child because it is too close, having intruded into the Keep Out Zone (KOZ).
Our co-pending application Ser. No. 08/957,730, filed Oct. 23, 1997, entitled KEEP OUT ZONE INCURSION FAST SENSING MODE FOR AIRBAG DEPLOYMENT SYSTEMS, now U.S. Pat. No. 6,249,729, issued Jun. 19, 2001 discloses a KOZI sensing system applicable to the present invention. This application relates to AOS systems for sensing the nature or type of occupant and the location of the occupant with respect to the vehicle interior, and more particularly the occupant seat and dashboard or instrument panel to develop a signal usable by the ADS.
The AOS and KOZI sensors may employ various sensor means. For example ultrasonic active transmission/reception sensors and infrared passive sensors may be used, either alone or in combination. Specific "zones" of the vehicle interior are sampled by each system with respect to a front passenger seat: the AOS sensor detecting the occupancy state of the passenger seat area; and the KOZI sensor detecting the incursion status of a "keep-out zone", generally defined by an area near the instrument panel forward of the passenger seat. In view of the different sampling target zones, these types of sensors have different mounting orientation requirements. The AOS electronics may be located in a console mounted in or on the headliner or header. The AOS and KOZI sensors may be mounted in the console or some other location in the interior, in which case they are connected to the console signal processing electronics by wiring in the headliner. The usual places for mounting of the AOS sensors, including a look-down KOZI sensor, are in the headliner or on the IP.
Automotive rear-view mirrors and their mounting brackets present a possible location for mounting sensors, particularly KOZI sensor(s). However, several problems for this location arise from the design and construction of conventional rear-view mirrors. In modern automobiles the mirror is typically independently supported by a bracket glued or bonded to the front windshield. This does not provide a protected path for wiring leading from the sensors to the AOS console as wiring bonded to the windshield is very vulnerable to physical wear and solar damage. In addition, such wiring would likely be damaged and require replacement in the event that the windshield is replaced, adding to the cost, time and inconvenience of windshield repair and AOS maintenance, particularly the calibration of these sensitive instruments. In addition, the sensors themselves may be damaged and/or become misaligned in the process of removing the mirror and its re-mounting during windshield replacement.